Enteridium lycoperdon, the False Puffball, is in fact not a fungus but a slime mold. 

It is commonly found on the dead wood of broad leaved trees. The mold starts out as a soft white mass which then develops a silver papery skin. The skin then splits, revealing a dark brown spore mass which crumbles away, releasing the spores into the wind. 

Seen here on the stem of Griselinia littoralis

(Source: , via mycology)

mold nature false puffball